I am trying to find a certain text in any text node in a document, so far my statement looks like this:
doc.xpath("//text() = 'Alliance Consulting'") do |node|
...
end
This obviously does not work, can anyone suggest a better alternative?
This expression //text() = 'Alliance Consulting' evals to a boolean.
In case of this test sample:
<r>
<t>Alliance Consulting</t>
<s>
<p>Test string
<f>Alliance Consulting</f>
</p>
</s>
<z>
Alliance Consulting
<y>
Other string
</y>
</z>
</r>
It will return true of course.
Expression you need should evaluate to node-set, so use:
//text()[. = 'Alliance Consulting']
E.g. expression:
count(//text()[normalize-space() = 'Alliance Consulting'])
against the above document will return 3.
To select text nodes which contain 'Alliance Consulting' in the whole string value (e.g. 'Alliance Consulting provides great services') use:
//text()[contains(.,'Alliance Consulting')]
Do note that adjacent text nodes should become one after parser gets to the document.
Related
In this xpath:
/A/B[C='hello']
Is C="hello" some kind of syntactic shortcut for C[text()='hello']? Is it documented anywhere?
Edit: Okay, I discovered one difference: C= returns all the text nodes in C and C's children, while C[text()= returns only the text nodes in C.
Now, suppose I have the XML:
<root>
<A>
<B>
<C>hello<E>EEE</E>world</C>
<D>world</D>
</B>
<B>
<C>goodbye</C>
<D>mars</D>
</B>
</A>
</root>
How would I choose the B node containing the first C node using the syntax C[text()=? I can get the B node using the C= syntax like this:
/root/A/B[C="helloEEEworld"]
But this doesn't work:
/root/A/B[C[text()="helloworld"]]
nor do these:
/root/A/B[C[text()="hello world"]]
/root/A/B[C[text()="helloEEEworld"]]
Hmmm...this works:
/root/A/B[C[text()="hello"]]
Why is that? Does text() only return the first text node? According to the W3C, text() returns all text node children of the context node.
text() really returns all text node children as list of nodes
When you use /root/A/B[C[text()="hello"]] you mean fetch B node with C child that any direct child node is equal to "hello".
In the same way you can match it by :
/root/A/B[C[text()="world"]]
or explicitly specify that you want to get node by exact first or second direct child text node:
/root/A/B[C[text()[1]="hello"]]
/root/A/B[C[text()[2]="world"]]
If you want to match required node by its complete text content you can use
/root/A/B[C[.="helloEEEworld"]]
or
/root/A/B[C="helloEEEworld"]
C in the predicate expression [C='hello'] returns all C elements that is direct child of context element which is B. So the entire predicate is a boolean expression that contains comparison between a node-set and a string (notice that element is a type of node in XPath data model), and behavior of this case is documented in the spec as follows :
If one object to be compared is a node-set and the other is a string, then the comparison will be true if and only if there is a node in the node-set such that the result of performing the comparison on the string-value of the node and the other string is true. If one object to be compared is a node-set and the other is a boolean, then the comparison will be true if and only if the result of performing the comparison on the boolean and on the result of converting the node-set to a boolean using the boolean function is true. [source]
C='hello' in /A/B[C='hello'] will be evaluated to true if any of the C elements, after converted to string, equals 'hello'. So it is more of a shortcut for C[string()='hello'] if you will.
"Hmmm...this works:
/root/A/B[C[text()="hello"]]
Why is that? Does text() only return the first text node? According to the W3C, text() returns all text node children of the context node."
Instead of the first text node, text() in this context returns all direct child text nodes. This is because child:: is the default axis in XPath. Contrasts your XPath with the equivalent verbose version of it :
/child::root/child::A/child::B[child::C[child::text()="hello"]]
Basically I need to scrape some text that has nested tags.
Something like this:
<div id='theNode'>
This is an <span style="color:red">example</span> <b>bolded</b> text
</div>
And I want an expression that will produce this:
This is an example bolded text
I have been struggling with this for hour or more with no result.
Any help is appreciated
The string-value of an element node is the concatenation of the string-values of all text node descendants of the element node in document order.
You want to call the XPath string() function on the div element.
string(//div[#id='theNode'])
You can also use the normalize-space function to reduce unwanted whitespace that might appear due to newlines and indenting in the source document. This will remove leading and trailing whitespace and replace sequences of whitespace characters with a single space. When you pass a nodeset to normalize-space(), the nodeset will first be converted to it's string-value. If no arguments are passed to normalize-space it will use the context node.
normalize-space(//div[#id='theNode'])
// if theNode was the context node, you could use this instead
normalize-space()
You might want use a more efficient way of selecting the context node than the example XPath I have been using. eg, the following Javascript example can be run against this page in some browsers.
var el = document.getElementById('question');
var result = document.evaluate('normalize-space()', el, null ).stringValue;
The whitespace only text node between the span and b elements might be a problem.
Use:
string(//div[#id='theNode'])
When this expression is evaluated, the result is the string value of the first (and hopefully only) div element in the document.
As the string value of an element is defined in the XPath Specification as the concatenation in document order of all of its text-node descendants, this is exactly the wanted string.
Because this can include a number of all-white-space text nodes, you may want to eliminate contiguous leading and trailing white-space and replace any such intermediate white-space by a single space character:
Use:
normalize-space(string(//div[#id='theNode']))
XSLT - based verification:
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="/">
"<xsl:copy-of select="string(//div[#id='theNode'])"/>"
===========
"<xsl:copy-of select="normalize-space(string(//div[#id='theNode']))"/>"
</xsl:template>
</xsl:stylesheet>
when this transformation is applied on the provided XML document:
<div id='theNode'> This is an
<span style="color:red">example</span>
<b>bolded</b> text
</div>
the two XPath expressions are evaluated and the results of these evaluations are copied to the output:
" This is an
example
bolded text
"
===========
"This is an example bolded text"
If you are using scrapy in python, you can use descendant-or-self::*/text(). Full example:
txt = """<div id='theNode'>
This is an <span style="color:red">example</span> <b>bolded</b> text
</div>"""
selector = scrapy.Selector(text=txt, type="html") # Create HTML doc from HTML text
all_txt = selector.xpath('//div/descendant-or-self::*/text()').getall()
final_txt = ''.join( _ for _ in all_txt).strip()
print(final_txt) # 'This is an example bolded text'
How about this :
/div/text()[1] | /div/span/text() | /div/b/text() | /div/text()[2]
Hmmss I am not sure about the last part though. You might have to play with that.
normal code
//div[#id='theNode']
to get all text but if they become split then
//div[#id='theNode']/text()
Not sure but if you provide me the link I will try
I am trying to find a way to search for a string within nodes, but excluding ythe content of some subelements of those nodes. Plain and simple, I want to search for a string in paragraphs of a text, excluding the footnotes which are children elements of the paragraphs.
For example,
My document being:
<document>
<p n="1">My text starts here/</p>
<p n="2">Then it goes on there<footnote>It's not a very long text!</footnote></p>
</document>
When I'm searching for "text", I would like the Xpath / XQuery to retrieve the first p element, but not the second one (where "text" is contained only in the footnote subelement).
I have tried the contains() function, but it retrieves both p elements.
Any help would be much appreciated :)
I want to search for a string in
paragraphs of a text, excluding the
footnotes which are children elements
of the paragraphs
An XPath 1.0 - only solution:
Use:
//p//text()[not(ancestor::footnote) and contains(.,'text')]
Against the following XML document (obtained from yours but added p s within a footnote to make this more interesting):
<document>
<p n="1">My text starts here/</p>
<p n="2">Then it goes on there
<footnote>It's not a very long text!
<p>text</p>
</footnote>
</p>
</document>
this XPath expression selects exactly the wanted text node:
My text starts here/
//p[(.//text() except .//footnote//text())[contains(., 'text')]]
/document/p[text()[contains(., 'text')]] should do.
For the record, as a complement to the other answers, I've found this workaround that also seems to do the job:
//p[contains(child::text()|not(descendant::footnote), "text")]
Given the following fragment of html:
<fieldset>
<legend>My Legend</legend>
<p>Some text</p>
Text to capture
</fieldset>
Is there an xpath expression that will return only the 'Text to capture' text node?
Trying /fieldset/text() yields three nodes, not just the one I need.
Assuming what you want is the text node containing non whitespace text :
//fieldset/text()[normalize-space(.)]
If what you want is the last text node, then:
//fieldset/text()[last()]
I recommend you accept Steven D. Majewski's answer, but here is the explanation (text nodes highlighted with square brackets):
<fieldset>[
]<legend>My Legend</legend>[
]<p>Some text</p>[
Text to capture
]</fieldset>
so /fieldset/text() returns
"\n "
"\n "
"\n Text to capture\n"
And this is why you want /fieldset/text()[normalize-space()], and you want the result trimmed before use.
Also note that the above is short for /fieldset/text()[normalize-space(.) != '']. When normalize-space() returns a non-empty string, the predicate evaluates to true, while the empty string evaluates to false.
doc = Nokogiri::HTML(open(url)).xpath("//*")
.xpath("//*[br]/text()[string-length(normalize-space()) != 0]")
.wrap("<span></span>")
puts doc
it just returns the text ... i was expecting the full html source with now wrapped around the specified xpath elements.
Try
doc = Nokogiri::HTML(open(url)).xpath("//*")
.xpath("//*[br and text()[string-length(normalize-space()) != 0]]")
.wrap("<span></span>")
puts doc
What your XPath does is it fetches the non-empty text nodes. Which by their very definition don't contain any markup.
In contrast, my XPath fetches any node that contains at least one <br> and at least one non-empty text node.